A prominent environmental group says the last virgin rainforests in the Asia-Pacific region - the vast tracts of Papua Island - are under threat from illegal loggers. A three-year investigation reveals the forests are being illegally stripped to make hardwood flooring worth billions of dollars for the Chinese and western markets.

Indonesia has some of the last untouched rainforests in the world, but experts say it also has the worst rate of deforestation.

The London-based Environmental Investigation Agency, or E.I.A., and Telapak from Indonesia have spent three years looking at the trade in a wood called merbau.

Merbau is a dark hardwood with a rich grain and is particularly popular for flooring. Millions of cubic meters of the wood are being illegally felled in the rainforests of Indonesia's Papua Province and illegally shipped to China for processing.

Julian Newman of the E.I.A. helped compile the report on the illicit logging trade and its threat to the environment.

"We believe this is one of the biggest log smuggling rackets in the world. It's a huge problem for Papua," he said. "We think that about 20 fully laden cargo ships are leaving Papua for China every month. Now Papua is part of the last intact forests in the Asia-Pacific, and if it carries on at this rate those forests will be seriously depleted."

It is a hugely lucrative trade: a cubic meter of merbau, for which local Papuans are paid $1, can be made into 26 square meters of flooring, which sells for nearly $2300 in New York or London.

The E.I.A. and Telapak say the problem needs a twofold solution. The trade is already illegal under Indonesian law, but bribing officials often circumvents it. So better anti-corruption enforcement is needed. But the report also says that consumers have a responsibility to stop buying rainforest hardwoods that have not come from independently verified sources.

Ecologists say that only five percent of the huge rainforests that used to cover much of the Asia-Pacific region are still untouched. And activists say that as the Chinese economy matures, adding a billion more consumers to put further pressure on the environment, the little that remains is under increasing threat.